KR20130117565A - System for providing composite image with image brightness control function and method for controlling image brightness - Google Patents

Abstract

PURPOSE: A synthetic image providing system which enables an image brightness control and an image brightness controlling method thereof are provided to make the brightness of a synthetic image uniform in case of synthesizing multiple photographic images. CONSTITUTION: A communication unit (600) communicates with multiple photographing devices. An image processing unit (300) includes a brightness density calculating unit (321), a similarity measuring unit (322), a parameter acquisition unit (323), and a parameter transmitting unit (324). The image processing unit determines a gain value of any one photographing device among the multiple photographing devices as a setting parameter based on inputted images. The image processing unit delivers the set setting parameter to the rest of the photographing devices except the one photographing device through the communication unit. [Reference numerals] (100) First camera; (110) Second camera; (120) Third camera; (130) Fourth camera; (200) Image input unit; (310) Image synthesizing unit; (321) Brightness density calculating unit; (322) Similarity measuring unit; (323) Parameter acquisition unit; (324) Parameter transmitting unit; (400) Image output unit; (500) Display unit; (600) Communication unit; (AA) Data communication; (BB) First image; (CC) Second image; (DD) Third image; (EE) Fourth image

Description

System for providing composite image with image brightness control function and method for controlling image brightness

The present invention relates to an imaging system, and more particularly, to a composite image providing system for synthesizing and providing images input from a plurality of photographing apparatuses into a single image.

1 is a block diagram of a conventional composite image providing system.

As shown, the composite image providing system includes a plurality of photographing apparatuses 10, 20, 30, and 40, an image controller 50, and a display apparatus 60. The photographing apparatuses 10, 20, 30, and 40 are cameras for photographing the front, rear, left, and right sides of the vehicle. The image controller 50 is a controller that receives camera images and synthesizes them into a single image. It is a device to display. Each of the photographing apparatuses 10, 20, 30, and 40 transmits an image to the image controller 50 by automatically adjusting gain according to the degree of ambient brightness. The image controller 50 may be an electronic control unit (ECU), a plurality of analog / digital converters 51, 52, 53, 54, an image synthesizer 55, and a digital / analog converter 56. ). The analog / digital converters 51, 52, 53, and 54 convert analog image signals input from the camera into digital image signals. The image synthesizer 55 receives the digital image signals and synthesizes them into a single image through distortion correction and synthesis logic. The digital / analog converter 56 converts the single digital video signal synthesized by the video synthesizing unit 55 into an analog video signal and outputs the analog video signal to the display device 60. Accordingly, the display device 60 displays a single image obtained by synthesizing four camera images.

In the conventional method, as shown in FIG. 1, the image is input by unidirectional communication, and the brightness of each camera is adjusted so that the image is input. Therefore, the color and brightness of the image displayed on the screen is difficult to harmonize. In particular, in the case of a system for synthesizing images using multiple cameras in a vehicle, since the environment changes by time, vehicle position, and posture, heterogeneity occurs due to a difference in brightness of the synthesized screen when each specific gain value is used.

An object of the present invention is to provide a technical solution that can equalize the brightness of a synthesized image when synthesizing a plurality of captured images.

An image brightness controllable composite image providing system for synthesizing and providing images input from a plurality of photographing apparatuses into a single image according to an aspect of the present invention for communicating the plurality of photographing apparatuses. A gain value of any one of the plurality of photographing apparatuses is determined as a setting parameter based on the communication unit and the input images, and the determined setting parameter is determined through the communication module. It includes an image processing unit for transferring to the remaining photographing devices.

The image processor may include: a brightness density calculator configured to calculate brightness densities of the input images; a similarity measurer configured to measure the similarity by comparing the calculated brightness densities with a reference brightness density; and the image having the highest measured similarity. And a parameter obtaining unit which determines and obtains an input gain value of the corresponding photographing apparatus as a setting parameter, and a parameter transferring unit which transmits the obtained setting parameter to the remaining photographing apparatuses other than the photographing apparatus.

On the other hand, the image brightness control method of the imaging system for synthesizing the images input from the plurality of imaging devices according to an aspect of the present invention to provide a single image to achieve the above technical problem is input from a plurality of imaging devices Calculating brightness densities of images, comparing each of the calculated brightness densities with a reference brightness density, and obtaining a gain value from a corresponding photographing apparatus that inputs the image having the highest measured similarity level; And transmitting the obtained gain value to photographing apparatuses other than the photographing apparatus.

According to the present invention, the effect of minimizing the brightness mismatch occurring in the synthesis of multiple camera images is created. Accordingly, it is possible to minimize the heterogeneity caused by the brightness mismatch generated when the user views the composite image, thereby contributing to the improvement of overall product quality.

1 is a block diagram of a conventional composite image providing system.
2 is a block diagram of a composite image providing system capable of controlling image brightness according to an embodiment of the present invention.
3 is a diagram illustrating a reference density graph and a brightness density graph for each camera image.
4 is a flowchart illustrating an image brightness control method according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and further aspects of the present invention will become more apparent from the following detailed description of preferred embodiments with reference to the accompanying drawings. Hereinafter, the present invention will be described in detail to enable those skilled in the art to easily understand and reproduce the present invention.

2 is a block diagram of a composite image providing system capable of controlling image brightness according to an embodiment of the present invention.

In one embodiment, the plurality of photographing apparatus is composed of the first camera 100, the second camera 110, the third camera 120 and the fourth camera 130. However, the number of imaging devices may be smaller or larger. The first camera 100, the second camera 110, the third camera 120, and the fourth camera 130 photograph different areas. For example, when the system is implemented in a vehicle, the first camera 100 photographs the front of the vehicle, the second camera 110 photographs the rear of the vehicle, and the third camera 120 photographs the left side of the vehicle. The fourth camera 130 photographs the right side of the vehicle. The image input unit 200 receives images input from the cameras and outputs the images to the image processor 300. The image input unit 200 may include analog / digital converters that convert analog image signals input from cameras into digital image signals. The image processor 300 includes an image synthesizer 310 and a brightness controller 320. The image synthesizer 310 synthesizes the camera images input through the image input unit 200 into a single image, and the image output unit 400 outputs the synthesized image to the display unit 500. ) Displays the synthesized image. The image output unit 400 may include a digital / analog converter for converting the synthesized digital video signal into an analog video signal. The image input unit 200, the image processor 300, and the image output unit 400 may be implemented as one electronic control unit.

Meanwhile, the brightness controller 320 determines a gain value of any one of a plurality of cameras as a setting parameter based on the first to fourth images input through the image input unit 200, and determines the determined setting parameter as a communication unit ( To the remaining cameras. The cameras adjust the gain with the gain value. This will be described in detail. The brightness controller 320 includes a brightness density calculator 321, a similarity measurer 322, a parameter acquirer 323, and a parameter transmitter 324. The brightness density calculator 321 calculates the brightness density of the captured RAW image input from each camera. In one embodiment, the brightness density calculator 321 analyzes the input image of each camera by calculating a brightness density graph of the RAW image input from each camera. An example of the graph analyzed is shown in FIG. 3. As shown in FIG. 3, (a) is a brightness density graph analyzed for the first image, (b) is a brightness density graph analyzed for the second image, and (c) is analyzed for the third image. Brightness density graph, and (d) is a brightness density graph analyzed for the fourth image. And (e) is a reference brightness density graph, which is data previously stored in memory.

The similarity measurer 322 compares the brightness density graphs calculated by the brightness density calculator 321 with the reference brightness density graph, respectively. That is, the similarity measuring unit 322 compares (a) and (e) of FIG. 3 to measure similarity, compares (b) and (e) to measure similarity, and measures (c) and (e). The similarity is measured by comparison, and the similarity is measured by comparing (d) and (e). In the example of FIG. 3, since the brightness density graph of the image of the fourth camera 130 is the most similar to the reference brightness density graph among the brightness density graphs of the camera images, the result will be similar to the fourth image.

The parameter obtaining unit 323 selects a camera that inputs the image having the highest similarity measured by the similarity measuring unit 322 as a representative camera (fourth camera), and sets a gain value of the fourth camera 130 as a setting parameter. The gain value of the fourth camera 130 is obtained. Specifically, the parameter obtaining unit 323 obtains a gain value from the fourth camera 130 through the communication unit 600, the fourth camera 130 is optimized by using the AGC (Auto Gain Control) function therein The calculated gain value is calculated and the calculated value is transferred to the parameter obtaining unit 323. Accordingly, the parameter obtaining unit 323 obtains a gain value of the fourth camera 130 which is a setting parameter. The parameter transfer unit 324 transmits the gain value of the fourth camera 130 obtained by the parameter acquirer 323 through the communication unit 600 to the first camera 100, the second camera, and the third camera 120. To pass). Accordingly, the first camera 100, the second camera, and the third camera 120 receive the gain value of the fourth camera 130 and adjust the received gain value. Accordingly, the brightness of the synthesized image synthesized by the image synthesizing unit 310 and displayed on the display unit 500 is uniform.

4 is a flowchart illustrating an image brightness control method according to an embodiment of the present invention.

The image processor 300 calculates brightness densities by analyzing images input from the first camera 100, the second camera 110, the third camera 120, and the fourth camera 130, respectively, as the photographing apparatus. S100). As described above, the image processor 300 calculates a brightness density graph as illustrated in FIGS. 3A to 3D with respect to the first to fourth images. The image processor 300 compares the calculated brightness density graph with a reference brightness density graph as illustrated in (e) of FIG. 3 to measure similarity. The image processor 300 selects the image having the highest similarity measured as the representative image in FIGS. 3A to 3D (S300). The image processor 300 obtains a gain value of the corresponding camera (representative camera) inputting the representative image (S400). For example, when the image processor 300 requests a gain value from the representative camera through data communication, the representative camera calculates an optimized gain value by using an internal AGC (Auto Gain Control) function and calculates the calculated value. Is transmitted to the parameter obtaining unit 323. Accordingly, the image processor 300 acquires a gain value of the representative camera. The image processor 300 transmits the obtained gain value to the remaining cameras except for the representative camera, and thus sets the same gains as the gain values of the representative camera.

So far I looked at the center of the preferred embodiment for the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

100: first camera 110: second camera
120: third camera 130: fourth camera
200: image input unit 300: image processing unit
310: image synthesis unit 320: brightness control unit
321: brightness density calculation unit 322: similarity measurement unit
323: parameter acquisition unit 324: parameter delivery unit
400: image output unit 500: display unit
600: communication unit

Claims (4)

In the composite image providing system for synthesizing the images input from a plurality of photographing apparatus into a single image,
A communication unit communicating with the plurality of photographing apparatuses; And
Based on the input images, a gain value of any one of the plurality of photographing apparatuses is determined as a setting parameter, and the determined setting parameter is photographed with the exception of any one photographing apparatus through the communication module. An image processor for transmitting to devices;
Image brightness controllable composite image providing system comprising a. The image processing apparatus of claim 1, wherein the image processor comprises:
A brightness density calculator for calculating brightness densities of the input images;
A similarity measurer for measuring similarity by comparing the calculated brightness densities with reference brightness densities;
A parameter obtaining unit which determines and obtains a gain value of a corresponding photographing apparatus that inputs the measured image having the highest similarity as a setting parameter; And
A parameter transfer unit configured to transfer the obtained setting parameter to remaining photographing devices except the corresponding photographing device;
Image brightness controllable composite image providing system comprising a. 3. The method according to claim 1 or 2,
The plurality of photographing apparatuses, the image brightness controllable composite image providing system, characterized in that for photographing different areas of the front, rear, left and right areas of the vehicle. In the image brightness control method of an imaging system for providing a combination of images input from a plurality of imaging devices into a single image,
Calculating brightness densities of images inputted from a plurality of photographing apparatuses;
Measuring similarity by comparing each of the calculated brightness densities with a reference brightness density;
Acquiring a gain value from a corresponding photographing apparatus that inputs the measured image having the highest similarity; And
Transmitting the obtained gain value to photographing apparatuses other than the photographing apparatus;
Image brightness control method comprising a.

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